List of top Questions asked in KEAM

The significant result deduced from the Rutherford’s scattering experiment is that

The half-life of a radioactive substance is 20 minutes. The time taken between 50% decay and 87.5% decay of the substance will be

The ratio of the surface area of the nuclei \(_{52}\text{Te}^{125}\) to that of \(_{13}\text{Al}^{27}\) is

Identify the mismatch in the following

The apparent flattening of the sun at sunset and sunrise is due to

The polarising angle for a medium is found to be \( 60^\circ \). The critical angle of the medium is

Light of wavelength 5000 \r{A is incident normally on a slit of width $2.5 \times 10^{-4}$ cm. The angular position of second minimum from the central maximum is}

In Young's double slit experiment, to increase the fringe width

In an LCR series circuit, at resonance

In a plane electromagnetic wave, the electric field of amplitude \( 1 \text{ V m}^{-1} \) varies with time in free space. The average energy density of magnetic field is (in \( \text{Jm}^{-3} \))

Which one of the following is the property of a monochromatic, plane electromagnetic wave in free space?

A conducting ring of radius 1 m kept in a uniform magnetic field B of 0.01 T, rotates uniformly with an angular velocity 100 rad s\(^{-1}\) with its axis of rotation perpendicular to B. The maximum induced emf in it is

A step down transformer increases the input current 4 A to 24 A at the secondary. If the number of turns in the primary coil is 330, the number of turns in the secondary coil is

A bar magnet of moment of inertia \(9 \times 10^{-5} \text{ kg m}^2\) placed in a vibration magnetometer and oscillating in a uniform magnetic field \(16\pi^2 \times 10^{-5} \text{ T}\) makes 20 oscillations in 15 s. The magnetic moment of the bar magnet is

If a magnetic dipole of moment M situated in the direction of a magnetic field B is rotated by \(180^\circ\), then the amount of work done is

The polarity of induced emf is given by

If the radius of the dees of cyclotron is \(r\), then the kinetic energy of a proton of mass \(m\) accelerated by the cyclotron at an oscillating frequency \(\nu\) is

Identify the correctly matched pair

If the ammeter A shows a zero reading in the circuit shown below, the value of resistance R is

Five cells each of emf E and internal resistance \(r\) send the same amount of current through an external resistance R whether the cells are connected in parallel or in series. Then the ratio \( \left( \frac{R}{r} \right) \) is

The magnitude of the magnetic field inside a long solenoid is increased by

The power dissipated in the transmission cables carrying current I and voltage V is inversely proportional to

A rigid container with thermally insulated walls contains a gas and a coil of resistance 50 \(\Omega\), carrying a current of 1 A. The change in internal energy of the gas after 2 minutes will be

The time period of revolution of a charge \(q_1\) and of mass \(m\) moving in a circular path of radius \(r\) due to Coulomb force of attraction with another charge \(q_2\) at its centre is

A point charge of 2 C experiences a constant force of 1000 N when moved between two points separated by a distance of 2 cm in a uniform electric field. The potential difference between the two points is